What is soil testing?
Soil testing is a very useful tool for the farmers to determine the fertility status of the soil. It includes various chemical processes to determine amount of available plant elements/nutrients in the soil, in addition gives details on the chemical, physical and biological properties that are vital for plant nutrition, or “soil health”. Therefore, based on the test results recommendations are made to make amendments to rectify soil problem, or to apply appropriate fertilizer to enhance soil fertility with respect to different crops. (S. K. Das, R. K. Avasthe). Soil testing gives an overall assessment of essential elements/minerals or individual parameters in soil in terms of quality and quantity of each mineral with respect to their normal range to help increase crop/plant yield (E. J. Kamprath; D. B. Beegle et al.)
Aims of soil testing:
- To quantify elements/nutrients availability in the soil samples.
- To determine the range of available nutrients and simultaneously investigate nutrient management.
- To investigate nutrient deficiencies, toxicities, or imbalances, identifying “hidden hunger”, to help increase crop/plant yield
- To evaluate the results to determine amount of fertilizer required.
- To predict of productivity of crop response to fertilization.
- To calculate probability of profit by soil fertilization to increase bushels.
How is soil testing done?
Soil testing involves following steps:
- Collecting soil samples from fields
- Chemical analysis of samples
- Evaluation and interpretation of results
- Suggestion of any amendments or addition of fertilizers or manures required to the soil.
How to do Soil sampling?
Materials and tools requirement for soil sample collection:
- A soil probes or spade
- A clean plastic bucket
- A trowel
- Pen/Permanent markers
- Sample bags. (Soil testing laboratories will provide wax-lined sample bags. In lieu of laboratory- provided bags, consider using paper bags or zip-top bags)
- Clipboard and paper or field notebook
- Optional: GPS-enabled smartphone or handheld GPS-unit
Soil Sampling Procedure:
1. Before arriving to the field, determine the number and approximate location of soil samples.
2. Once the appropriate materials have been collected, travel to the first sampling location.
3. At the sample location, remove any crop residue from the soil surface.
4. Insert the soil probe to the desired depth. Take care to ensure the probe is inserted vertically into the soil and not tilted to the side. Remove the probe and transfer the soil core from the probe into a bucket.
It is recommended that samples be taken from the following depths to get the best estimate of soil nutrient levels to optimize nutrient management:
• 0 to15cm (0to6in)
• 15 to 30cm (6to12in)
• 30 to 60cm (12to24in)
5. Move to a new location and repeat Steps 3 and 4.
6. Continue this process of sample collection at new locations until you have collected enough samples. Typically, a composite sample should be comprised of between 10 and 20 subsamples. The more subsamples you add into a composite, the more reliable a sample becomes.
7. Using the trowel, thoroughly mix the soil in the bucket until you have a homogeneous mixture.
8. Place 1-2 cups of the mixture into a sample bag. Using pen/permanent marker, label the bag with a unique name. Names should contain identifiers to the field location and sample number.
How is soil sample testing or analysis done?
Soils contain large amounts of essential nutrients for plants, however a small amount (usually less than 1%) of available nutrients that can be extracted and used by the plants. Soil testing involves extraction of a portion of nutrients from soil samples and analyzing that extract. Thus, the test results indicate the amount of nutrients that a plant root can extract from soil.
Soil testing involves different methods for determination of basic plant nutrients using ICP-OES instrument along with chemical analysis with involves determination of pH, organic matter, lime requirements, potassium magnesium and calcium saturation, nitrate-nitrogen, ammonium nitrogen, chloride, and salinity in terms of electrical conductivity.
How to interpret the soil test results?
The soil test results can be divided into two sections:
Table sections: Details out overall assessment of essential elements/minerals or individual parameters in soil sample in terms of quality and quantity of each mineral with respect to their tested range. The detailing and information included in the table after soil testing in same or matches other lab reports for soil generated across Canada.
Graph section: Details out the essential elements/minerals or individual parameters in soil sample in terms of their tested range with respect to normal range optimum for soil health and plant growth. The detailing and information included in the graph after soil testing in unique to CAI lab reports across Canada. Our scientist at CAI have done extensive research, referred research articles, tested samples across Canada and classified to determine very low, low, high and very high range with respect to the normal range optimum for soil health and plant growth.
What does each parameter in the report says?
pH Level: indicates the soil’s level of acidity, or pH, which in term affects the availability conditions of nutrients to the plant. Soils pH of 6.0 to 7.0 are considered best for crop growth and fertilizer use, however Laboratory Services recommend pH of 6.5 is considered ideal.
Organic matter: determines soil health and soils with 3.5%+ of organic matter are considered best levels. It contributes to the physical, chemical, and biological properties of the soil.
Cation Exchange Capacity (CEC): measures the soil’s ability to hold and release positively charged nutrients (cations), such as potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na).
Lime requirement: indicates the amount of lime in tonnes per hectare required to raise the field pH level to 6.5. Soil pH levels increases more rapidly if lime is mixed with the soil.
Benefits of Soil Testing at CAI:
- Paramount testing platform with advanced and high-end instruments setup (Only company in this space that uses ICP-OES for sample and product testing)
- Our testing methods has been rigorously evaluated for detection limit, accuracy, precision, repeatability, and reproducibility.
- Our quality control protocols include control samples, reference standards and method blanks to confirm no cross-contamination and eliminate nonspecific/false results.
- Our suggestions include crop treatment based on the information gathered from the testing results and modelling results to help increase crop/plant yield.
- Based on the soil nutrient test levels the fertilizer/compost recommendations are made.
- We offer the services with best rates in the market.
- We have the quickest turnaround time.
- We have team of experienced Scientists and Agronomists.
- In addition to soil testing, we also offer Plant Tissue Sampling/Testing, Pathogen analysis, grain analysis, Customized Consortium culture and protocol applications etc.
- S. K. Das, R. K. Avasthe and S. K. Reza; Importance of Soil Testing in Organic Agriculture.
- R.D. Baker, Extension agronomist; Shane T. Ball, Extension agronomy specialist; Robert Flynn, assistant professor College of Agricultural, Consumer and Environmental Sciences New Mexico State University
- Importance of Soil Analysis; Tanja Folnovic, Agronomy Expert. https://blog.agrivi.com/post/importance-of-soil-analysis
- Understanding the Soil Test Report, NovaScotia Agriculture. https://novascotia.ca/agri/documents/lab-services/analytical-lab-understand-soil.pdf
- Relevance of Soil Testing to Agriculture and the Environment. Council for Agricultural Science and Technology (CAST) Issue Paper Number 15, June 2000. Eugene J. Kamprath; Douglas B. Beegle; Paul E. Fixen, Steven C. Hodges et al.
- Ministry of Agriculture, Food and Rural Affairs Soil Sampling and Analysis for Managing Crop Nutrients. http://www.omafra.gov.on.ca/english/engineer/facts/06-31.htm
- Soil Testing: What Should You Look For? – OMEX Agriculture Inc. Dr. DR. ABDEL EL HADRAMI. https://omexcanada.com/blog/soil-testing-what-should-you-look-for.
Soil health/balance is as important as health of a person, people focus on increasing cash crops and quantity of crops which ultimately affects the soil health. Thus, CIA team encourages the importance of soil testing to determine soil health/balance for each cropping season.